The phloem is indicated in red and the xylem is indicated in blue. Very recently, we have been able to visualize and quantify these streams, and this can also be seen in picture 2. But we know that within the stem, water with minerals (xylem) is continuously flowing from the roots to the leaves and at the same time, water with sugars that have been produced in the leaves (phloem) is flowing to the roots. At first sight, this picture only provides a static structure. The picture is obtained non-invasively with MRI (magnetic resonance imaging) in our lab. Picture 2 shows the cross section of the stem of a cucumber plant. With the use of our streak-camera setup we can excite all kinds of natural chromophores, fluorescent labels and amino acids from UV to infrared and monitor the dynamics on a time scale from sub picoseconds to many nanoseconds. To study molecular dynamics experimentally we make for instance use of ultra fast time-resolved fluorescence methods.
#Lab master life is strange movie#
Such a movie makes it immediately more clear that processes as replication, translation can occur but at the same time that they may also go wrong. It shows the amazing amount of dynamics occurring within only several nanoseconds. The result of such a molecular dynamics simulation can be seen upon clicking on picture 1, turning it into movie 1. However, applying the laws of physics, one can approximately calculate the forces between the different atoms, and accordingly the dynamics of the DNA molecule can be obtained with the use of fast computers. This is the kind of picture one can find in many textbooks and with the use of such a picture many aspects of the role and functioning of DNA can be explained. Picture 1 shows a rigid part of a double-stranded DNA molecule. Examples of dynamics at both levels are given below. It is the dynamics that plays a crucial role in biology, but also in our biophysical research, from the molecular level to the level of organisms. Biophysics is concerned with biological structure, DYNAMICS and function. There is one additional word missing in the definition above, which is of particular importance for our biophysical research. The distinction between the “live” (biology) and “dead” (physics) world is disappearing more and more. Not only do biophysicists provide and apply physical techniques, they also try to understand life processes and structures in terms of underlying physical laws and principles. However, this definition is not correct and covers only part of the truth. It is not strange that people then might think that biophysics is only meant to provide research tools for biologists and medics. This is for instance the definition that is used by the British Biophysical Society. What is Biophysics? People often tend to think that biophysics is the field, which applies techniques from the physical sciences to understanding biological structure and function.
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